Bycatch Reduction Deviceshttp://hdl.handle.net/20.500.12067/2112024-03-29T13:47:05Z2024-03-29T13:47:05ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Brunei DarussalamChokesanguan, BunditAnanpongsuk, SuppachaiSiriraksophon, SomboonHamid, Idrish Abdulhttp://hdl.handle.net/20.500.12067/5772023-04-20T03:50:49Z2003-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Brunei Darussalam
Chokesanguan, Bundit; Ananpongsuk, Suppachai; Siriraksophon, Somboon; Hamid, Idrish Abdul
SEAFDEC Training Department, in cooperation with the Brunei Darussalam Department of Fisheries conducted experiments on Juvenile and Trash Excluder Devices (JTEDs) during the year 2000 in Brunei Darussalam waters. The objective being to study the catch and release efficiency of juvenile and trash fish devices using differences in the escape opening of JTEDs. Two types of JTED namely a rigid sorting grid (bar spacing 30 mm.) and a two codend type (50/35 mm. codend mesh size) were designed. Five operations were carried out using the rigid sorting grid JTED and two codend types respectively. Separation efficiency by size in the same species between a body length (i), in the codend and body length (j) in the cover net is defined as y<sub>i</sub> + y<sub>j</sub> -1, where y<sub>i</sub> is the recovery ratio in the codend, that means the proportion of the catch number retained in the codend and y<sub>j</sub> is the recovery ratio in the cover net.
The recovery ratio from the codend of the rigid sorting grid JTED (bar space 30 mm.) of Nemipterus sp. with a body length 13.0 cm. was 0.83 while the recovery ratio in the cover net having the same body length was 0.17 which indicates that the thread fin bream group with a body length of 13.0 cm. can enter the codend rather than go into the cover net. For a two cover codend trawl net (50-35 mm. codend mesh size) the recovery ratio in the codend was 0.39, while the recovery ratio in cover net was 0.61, which indicates that this fish species may go into the cover net rather than remain in the codend. A comparison between the two types of JTED and the rigid sorting grid type with a bar spacing of 30 mm. shows that thread fin bream with a body length 13.0 cm has a higher recovery ratio in the codend than in two-cover codend type. This implies that the separation performance of the sieving grid of the JTED depends on the design of the releasing device, grid bar spacing and codend mesh size as well as the swimming ability of each species in the net.
2003-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in IndonesiaChokesanguan, BunditAnanpongsuk, SuppachaiChanrachkij, IsaraManajit, NoppornTampubolon, Gomal H.http://hdl.handle.net/20.500.12067/5782023-04-20T03:50:49Z2003-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Indonesia
Chokesanguan, Bundit; Ananpongsuk, Suppachai; Chanrachkij, Isara; Manajit, Nopporn; Tampubolon, Gomal H.
The experiment was conducted during August 2002 in the Bintuni Bay, Arafura Sea of East Indonesia using the commercial double-rigged trawler in order to examine the releasing ability of Juvenile and Trash Excluder Devices (JTEDs) in bottom trawl. This experiment was in the serial study of using the JTEDs under the program of selective fishing gear and practice for responsible fishing, sponsored mainly by FAO/GEF project. Three types of JTEDs (Rectangular, Semi-curve and Rigid sorting grid JTEDs) with 40 mm bar spacing were used in this experiment as 40mm bar spacing has been shown the best results for releasing the non-target catch and could maintain the maximum catch resulted from the previous experiments.
The results indicated that the rigid sorting grid JTED could give the escapement levels of about 79% of the total catch when it was about 25% for semi-curve and rectangular type JTED. However, it was observed that semi-curve JTED performed the highest ability in shrimp retention ratio as compared with another two type of JTED used in this experiment. It could be suggested that the effectiveness of the modifications for JTEDs used in the region could be further fine-tuned to improve the performance.
2003-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in MalaysiaChokesanguan, BunditAnanpongsuk, SuppachaiSiriraksophon, SomboonAli, Rosidihttp://hdl.handle.net/20.500.12067/5682023-04-20T03:50:49Z2002-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Malaysia
Chokesanguan, Bundit; Ananpongsuk, Suppachai; Siriraksophon, Somboon; Ali, Rosidi
This paper describes the results of the juvenile and trash fishes excluder device tests conducted aboard a Malaysian Fishing Trawler in cooperation with the Department of Fisheries, Malaysia. In particular, it provides estimates of Catch per Unit Effort (CPUE) of trawl fishery, catch composition in day and nighttimes, distribution of length-frequencies for the capture fishes and released fishes using different opening grid.
2002-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Brunei DarussalamChokesanguan, BunditAnanpongsuk, SuppachaiChanrachkij, IsaraYingyuad, WeerasakSuru, Bidin Binhttp://hdl.handle.net/20.500.12067/5922023-04-20T03:50:49Z2005-01-01T00:00:00ZStudy on Juvenile and Trash Excluder Devices (JTEDs) in Brunei Darussalam
Chokesanguan, Bundit; Ananpongsuk, Suppachai; Chanrachkij, Isara; Yingyuad, Weerasak; Suru, Bidin Bin
The SEAFDEC Training Department, in cooperation with the Department of Fisheries, Brunei Darussalam, conducted the second series of experiments on Juvenile and Trash Excluder Devices in Brunei Darussalam. The objective being to study the catching and release efficiency for juvenile and trash fishes using different escape openings of the JTEDs. The rigid sorting grid with a bar space of 1, 2 and 3cm were operated at 6 stations in daytime, 4 stations at night and at 2 special stations for the rigid sorting grid with a bar space 1 cm for sea trials. The rectangular shaped JTEDs and semi-curved d JTEDs were operated at 6 stations at night only. There were a total of 44 operations.
The CPUEs of the fish trawl net, operated in the northern areas of Brunei Darussalam were 283.27 kg/hr, about 54% in daytime and 46% at night. Escape rate percentages, by weight, of the trawl net with the rigid sorting grid JTEDs attached and having a bar space of 1, 2, 3cm, the rectangular shaped JTEDs and semi-curved JTEDs were 30.38, 77.67, 86.29, 40.03 and 12.77%, respectively. However there were some large fishes that could escape from the rigid sorting grid JTEDs with bar spacing of 2 and 3 cm of both the rectangular shaped JTEDs and semi-curved d JTEDs. The estimated selectivity curves were shown the sizes of Leiognathus ssp., which escaped from the rigid sorting grid JTEDs with bar spacing of 1, 2, 3cm in both the rectangular shaped JTEDs and semi-curved d JTEDs at L50, were 10.30, 13.29, 14.22, 4.28 and 9.16, respectively. The estimate selectivity curves were shown the sizes of Gerres ssp., which escaped from the rigid sorting grid JTEDs with bar spacing of 1, 2, 3cm of both the rectangular shaped JTEDs and semi-curved d JTEDs at L50, were 11.77, 13.40, 12.90, 11.91 and 10.01, respectively.
2005-01-01T00:00:00Z